Four short links: 23 July 2013

Page Speed is Only The Beginning — 73% of mobile internet users say they’ve encountered Web pages that are too slow. A 1 second delay can result in a 7% reduction in conversions.

Rate Limiting and Velocity Checking (Jeff Atwood) — I was shocked how little comprehensive information was out there on rate limiting and velocity checking for software developers, because they are your first and most important line of defense against a broad spectrum of possible attacks. It’s amazing how many attacks you can mitigate or even defeat by instituting basic rate limiting. (via Alex Dong)

Self-Assembling Multicopter (DIY Drones) — The true accomplishment of this research is that there is not one robot in control – each unit in itself decides what actions to take to keep the group in the air in what’s known as Distributed Flight Array. (via Slashdot)